back in the 1980s with the WalMartization of the labor force in the Retail and Service sectors. Before then you had people in those jobs that were in their career, making enough to buy a house, car and pay for the kids college. They would never be wealthy by any means but they could pay their bills, had health insurance and have a defined benefits pension to look forward to at retirement.
When more and more firms adopted the part time, lower wage, no benefits (if this one doesn't work out, just get another warm body) approach it was great short term for quarterly but they shot themselves in the foot long term. This shift in how companies operated created a complete missing generation in the Retail Sector that was pretty much nationwide. When I was in my 50s and working there was virtually no employees in their 40s and very few in their 30s. Now retired and going into the chain where I worked I look at the faces of 20 year olds in management positions that are completely unprepared with work experience or life skills for the jobs they hold.
They have now pretty much run through those who would fill those jobs and all the experienced help has either left, been laid off or retired, so now they all compete for the bottom of the barrel.